textproduct: Quad Cities

KEY MESSAGES

- Chances of showers (30-60%) and isolated thunderstorms will continue this afternoon and evening before tapering off late tonight, leading to a dry day Saturday.

- Heavy rainfall is expected Sunday morning through early Monday morning. Accumulations of 1-3+ inches are likely (50-80+%) south of Highway 30, with the heaviest rainfall expected to occur south of Interstate 80.

- Comfortable temperatures are expected to continue through much of next week as we stay under northwesterly flow.

SHORT TERM /THROUGH SATURDAY/

Issued at 208 PM CDT Fri Jun 19 2026

An area of scattered showers/isolated thunderstorms that has developed over central Iowa early this afternoon will continue to spread eastward into our area ahead of an approaching mid-level shortwave trough. Rainfall amounts should remain limited with these showers, thanks to lingering dry air in the low-levels below 700 mb per the latest HRRR, RAP, and RRFS soundings. The latest DVN 19.18z sounding also shows abundant dry air through the column, so this activity will have to do some work to overcome the dry air here. There could be some locally gusty winds under these showers, owing to the drier profile near the surface, with gusts to around 20 to 30 mph possible. We're also not outlooked for any strong/severe thunderstorms with this activity, so lightning appears to be the primary threat with any storms.

This activity should taper off late tonight as the mid-level shortwave quickly exits to the east and mid-level ridging takes its place. This ridging should help support a pretty pleasant day over the area Saturday, with plenty of sunshine and high temperatures warming to the upper 70s to lower 80s - pretty seasonal for this time of the year. However, things look to be more active for Sunday, which is discussed in detail in the Long Term section below.

LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/

Issued at 208 PM CDT Fri Jun 19 2026

The main focus for the long term period remains on a rather wet system that's expected to translate over the area early Sunday morning through early Monday morning. An approaching mid-level shortwave, with an attendant surface low is expected to translate through northern Missouri or across our southern forecast area (some uncertainty on the track remains). The exact surface low track will ultimately determine just how far north the area of rainfall will reach, but confidence remains high for heavy rainfall to occur at least along and south of Interstate 80. This area is expected to see the highest Pwat values with this system, with values between 1.5" up to 2.0" along our southern tier of counties. These values would be above 98 percent of climatology per the NAEFS ensembles, so this looks to be a rather anomalously moist system for this time of the year. We are just beginning to get into range of the REFS ensemble, and its 24-hour probability-matched mean QPF values through 00z/7 PM Monday along and south of Interstate 80 is around 1-3 inches. Given that our current flash flood guidance values are around 1.5 to 2.5 inches for these areas, this could be problematic for heavy rainfall/flash flooding. Given this set-up, WPC has expanded the Slight Risk (level 2 of 4) for excessive rainfall farther north, now over nearly the entire CWA. If this trend of heavy rainfall continues, we may need to consider a Flood Watch for portions of our forecast area for the flash flood threat. At the very least, this should exacerbate our ongoing flooding over area rivers.

In terms of the severe storm threat with Sunday's activity, there appears to be a lack of instability per the latest guidance (only a few hundred J/kg of SBCAPE per the REFS). However, deep-layer shear values appear to be decent, with values around 40-50 knots, so some strong to severe convection is possible, and SPC continues to have our southern areas (south of Highway 34) in a Marginal Risk (level 1 of 5). It does seem that the higher chances of severe weather will be to our south into Missouri and southern Illinois.

For Monday through Thursday next week, the pattern remains fairly active towards mid-week as a few upper-level disturbances move through the area, bringing more chances of showers/storms (20-50%). For Monday and Tuesday, these days appear very likely to remain dry under partly to mostly clear skies, thanks to an area of high pressure building across the western Great Lakes. Temperatures will also remain comfortable throughout the week, with highs warming to the 70s for most.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 620 PM CDT Fri Jun 19 2026

Upper level disturbance will bring mainly scattered rain showers to eastern Iowa and northern Illinois through 04z/20 with areas of MVFR conditions. Probability of a TSRA is under 10 percent. After 06z/20 a slow clearing of skies from west to east with winds under 10 knots. Winds will veer after sunrise Saturday to the northwest at 5 to 10 knots.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.